Conversion of nitrile to its corresponding amide using improved copper oxide catalyst

ABSTRACT

A process for catalytically hydrolyzing a nitrile to the corresponding amide by contacting the nitrile in the presence of water with an activated copper oxide.

United States Patent [191 Svarz Aug. 19, 1975 i 1 CONVERSION OF NITRILE TO ITS CORRESPONDING AMIDE USING IMPROVED COPPER OXIDE CATALYST [75] Inventor: Jerry J. Svarz, LaGrange, Ill.

[73] Assignee: Nalco Chemical Company, Oak

Brook, Ill.

[22] Filed: Nov. 29, I973 [21] Appl. No.: 420,037

Related US. Application Data [63] Continuation-impart of Ser. No. 292,2l6, Sept. 25,

1972, Pat. No. 3 346,495.

[52] US. Cl 260/561 N; 252/463; 260/557 R [51] Int. Cl. C07c 103/08 [58] Field Of Search 260/561 N, 561 R, 558 R,

Primary Examiner-C. Davis Attorney, Agent, or Firm-John G. Premo; Robert A. Miller [57] ABSTRACT A process for catalytically hydrolyzing a nitrile to the corresponding amide by contacting the nitrile in the presence of water with an activated copper oxide.

4 Claims, N0 Drawings CONVERSION OF NITRILIC TO ITS CORRESPONDING AMIDIC USING IMPROVED COPPER OXIDE CATALYS'I This is a continuation-in-part of my earlier liled application, Ser. No. 292,216, filed Sept. 25, 1972, now [1.5. Pat. No. 3,846,495.

INTRODUCTION This invention relates to a process for catalytically hydrolyzing a nitrile to the corresponding amide. The hydrolysis of nitriles to form the correspondi'ngamidcs and other hydrolysis products in the presence of acids and bases are well known to those skilled in the art as noted in [1.5. Pat. No. 3,381,034. The prior art teaches the use of copper-copper ion catalysts, reduced copper oxide catalysts, reduced copper chromium or copperaluminum oxide catalysts and other catalysts composed of heavy metal such as zinc, cadmium, chromium and silver. These catalysts as well as others are disclosed in [1.8. Pat. Nos. 3,381,034; 3,631,104; 3,642,894; 3,597,481 and 3,642,643. However, it has been determined that copper oxide, per so, does not work efficiently as a catalyst in the conversion of a nitrile to its corresponding amide. In all cases a reduced" copper oxide catalyst is mentioned and used in the prior art.

The present invention involves the activation of copper oxide to provide a catalyst useful in hydrolyzing a nitrile to its corresponding amide. It has been discovercd that by contacting the copper oxide with a dilute aqueous solution of an alkali metal hydroxide and powdered aluminum followed by filtering, washing and recovering the copper oxide, an activated catalyst is formed. The discovery of this improved method of preparing a copper oxide catalyst has resulted in a substantial increase in conversion of nitrile to amide.

OBJECTS It is therefore an object of this invention to provide an improved catalyst for hydrolyzing nitrile to the corresponding amide.

It is also an object of this invention to provide a process for hydrolyzing the nitrile to the corresponding amide, the improvement which comprises the reaction of nitrile in the presence of an improved catalyst composition.

It is a further object of this invention to provide a process for hydrolyzing aerylonitrile to aerylamide.

A still further object of this invention is to provide a process for hydrolyzing acrylonitrile to acrylamide, the improvement which comprises the reaction of acrylonitrile in the presence of an activated copper oxide cata lyst.

Further objects will appear hereinafter.

INVENTION This invention involves a process for catalytically hydrolyzing a nitrile to its corresponding amide using activated copper oxide as a catalyst. Basically, the preparation of the activated copper oxide catalyst involves the following steps:

A. Contacting an aqueous slurry of copper oxide for to 3 hours with a dilute aqueous solution of an alkali metal hydroxide and a powdered aluminum to yield a slurry containing 1 to 75% by weight of copper oxide and 1.0 to 90% by weight based on the copper oxide of powdered aluminum to form an activated copper oxide catalyst; and

B. Filtering, washing and recovering the copper oxide catalyst. v

'l'he first stepof the activation of copper oxide involves the contacting of copper oxide with a solution of alkali metal hydroxide and aluminum as described in step (Al above. ("opper oxide is added to a dilute aqueous solution jof tin alkali metal hydroxide. Thc Term copper oxide refers to and includes both c'uprous oxide and cupric oxide. Generally, the dilute aqueous solution of the alkali metal hydroxide is present in the range of 10 to 100% by weight based on copper oxide with the preferred range being 5 to 50% by weight. The concentration ofthc caustic solution may vary over a wide range. In general, the concentration of the caustic solution'is from 5 to 20% by weight. The preferred alkali metal hydroxides are sodium hydroxide and potassium hydroxide; Typically, it is desired to prepare a slurry which has from 1 to by weight of copper oxide.

In addition to the alkali metal hydroxide being added 'to the copper oxide, from 1.0 to by weight based performed with the temperature in the range of 0 to 90C Preferably the. temperature is within the range of 20 to 30C.

It has been determined that line and tin may be sub- 1 stituted for aluminum in the practice of this invention.

However, it should be pointed out that the use of zinc or tin does not provide as active of a catalyst as does the use of aluminum. The conversion of nitrile to amide may be increased by as much as 50%.

vAfter the reaction has been completed the supernatant liquid is decanted from the activated copper oxide and the solid catalyst is isolated and water washed. Generally, the solid catalyst is water washed with seven aliquots of water with each aliquot having an equivalent weight to that of the catalyst. Once the catalysthas been filtered and water washed it is recovered and the activated copper oxide catalyst is then ready for use in the hydrolysis of a nitrile to form an amide.

The nitriles which may be hydrolyzed by the catalysts prepared by the present invention may be aliphatic or aromatic nitriles with those nitriles containing up to 20 or more carbon atoms being preferred. For purposes of the invention, aromatic nitriles are defined as those ni- V trilcs having cyano groups attached to the aromatic nucleus. Representative examples of suitable nitriles include saturated aliphatic hydrocarbon nitriles such as iiidecenonitrile, maleonitrile, fumaronitrile, and the like; aromatic nitriles such as benzonitrile, ptoluonitrile, oz-naphthonitrilc, phthalonitrile and the like. Of the nitriles suitable for use in the invention, olefinic nitriles of 3 to 6 carbon atoms are especially preferred with thc'conversion of acrylonitrile to aerylamide being .of'special interest.

' The hydrolysis of the nitrile to the corresponding amide in the invention may be conducted in an essentially aqueous media. Excess water is the preferred solvent although other inert solvents such as dioxane. dimethylsulfoxidc. acetone, dimethyl ether of ethylene glycol or tetrahydrofuran, may he used. Any practical amount of water may be added. Molar excesses of water up to 50 mole of water to l mole of nitrile are suitable with excesses of less than 40:1 being preferred. In the practice of this invention, the nitrile may be added to the aqueous mix containing the copper cata lyst.

The temperature at which the nitriles are converted to the amides is basically a function of the reactants used in the process of the invention. Since the reaction of the present invention is a liquid phase hydrolysis, the melting and boiling points of the reaction mixture are the limiting factors of the range of reaction tempera tures. As a practical matter, the suitable rangeof temperatures is from to 400C. with 25 to 200C. being preferred. For unsaturated nitriles which tend to polymerize, a reaction temperature of less than 200C. is desirable.

The following examples further illustratethe discovery of this invention: 7

EXAMPLE I A 100 gram sample of cupric oxide, 250 grams of a 50% sodium hydroxide solution, 35 grams of powdered aluminum and 5.0 cc of N-butanol were added to a beaker with mixing. The temperature was maintained within the range of 25 to 30C. for 30 minutes. The

EXAMPLE 2 The following ingredients were used in this reaction:

50 grams of CuO 250 grams of 50% sodium hydroxide solution 370 cc of water cc of N-butanol I The sodium hydroxide solution, water, cuprous oxid and N-butanol were added to a beaker with mixing. The powdered aluminum was added over a l hour period holding the temperature within the range of 25 to 30C. After the one hour addition of powdered aluminum, the mixture was agitated for an additional 1 /2 hours and then diluted with 350 cc of water. The'oxide catalyst was isolated and water washed with nine separate aliquots of 75 cc water each. The final pH of the oxide slurry was 8.2.

EXAMPLE 3 Added to an autoclave with the following reactants were: a v

14.4 grams of filtered wet copper catalyst 148.0 grams of water 52.0 grams of acrylonitrile These reactants were added with mixing to an autoclave which was heated to 105C. After 2 and 4 hours the conversion of nitrile to amide was measured for each of the copper oxide catalysts as shown below in TABLE I.

TABLE l 70 Conversion Type 7 Hr. 4 Hr. 6 Hr.

Cu. .O 2.x: CuO 4.20 Activated CLIQO (Ex 1 62.4 79.2

Activated CuO (Ex 2) 44.

Similar results to those obtained in the above examples were obtained from the following nitriles tested: methacrylonitrile, acetonitrile, maleonitrile, benzonitrile and croton ic nitrile.

EXAMPLE 4 TABLE ll Pcrccnt Conversion Type 4 Hr.

Cu O CuO Activated Cu O (Ex I) 83.0 Activated CuO (Ex 2) 59.3

Similar results to those obtained in Table II were obtained at the following conditions: l05l 30C, at pressures of 6585 psig.

CONCLUSION The previous examples clearly show that copper oxide can be. activated by treatment with an alkali 'metal hydroxide with powdered aluminum. The increase in the conversion rate of a nitrile to its corresponding amide is substantially improved by the use of the catalystsof this invention. Incomparing the euprous oxide the conversion was increased from 2.85% to 62.4 and 79.2% for 2 and 4 hour conversions at 105C, respectively. For the cupric oxide, the conversion rate was increased from 4.2% to 44.8 and 55.0% for 2 and 4 hour conversions at 105C, respectively. Thus, there was a dramatic increase in the conversion of nitrile to amide in the activation of copper oxide using the procedure taught in this invention.

1 claim:

1. A process for catalytically hydrolyzing acrylonitrile to acrylamide, the improvement comprising contacting a reactant feed of acrylonitrile in the presence of water with an activated copper oxide prepared by the following steps:

A. Contacting an aqueous slurry of copper oxides for V; to 3 hours at a temperature within the range v 090C with a dilute aqueous solution of from 5-207r by weight of an alkali metal hydroxide and a powdered aluminum to yield a slurry containing l-71 by weight of copper oxide and l0 to by 6 hydroxide and potassium hydroxide.

3. A method of claim 1 wherein the concentration of powdered aluminum is 10 to 50% by weight of copper oxide.

4. A method of claim 1 wherein the activation is performed within the temperature range 20 to 30C. 

1. A PROCESS FOR CATALYTICALLY HYDROLYZING ACRYLONITRILE TO ACRYLAMIDE, THE IMPROVEMENT COMPRISING CONTACTING A REACTANT FEED OF ACRYLONITRILE IN THE PRESENCE OF WATER WITH AN ACTIVATED COPPER OXIDE PREPARED BY THE FOLLOWING STEPS: A. CONTACTING AN AQUEOUS SLURRY OF COPPER OXIDES FOR 1/2 TO 3 HOURS AT A TEMPERATURE WITHIN THE RANGE 0*-90*C WITH A DILUTE AQUEOUS SOLUTION OF FROM 5-20% BY WEIGHT OF AN ALKALI METAL HYDROXIDE AND A POWDERED ALUMINUM TO YIELD A SLURRY CONTAINING 1-75% BY WEIGHT OF COPPER OXIDES AND 10 TO 90% BY WEIGHT BASED ON SAID COPPER OXIDE OF POWDERED ALIMINUM TO FORM AN ACTIVATED COPPER OXIDE CATALYST. B. FILTERING, WASHING AND RECOVERING SAID COPPER OXIDE CATALYST.
 2. A method of claim 1 wherein the alkali metal hydroxide is selected from the group consisting of sodium hydroxide and potassium hydroxide.
 3. A method of claim 1 wherein the concentration of powdered aluminum is 10 to 50% by weight of copper oxide.
 4. A method of claim 1 wherein the activation is performed within the temperature range 20* to 30*C. 